The invention generally relates to the art of forming joints between lengths of so-called rigid tubing, and more particularly to an improved union, and method of employing the union, for forming an improved joint between lengths of malleable tubing.
As can be fully appreciated by those familiar with problems encountered in coupling lengths of tubing, formed of malleable stock, such as copper and the like, there currently exists a need for improved unions which facilitate a rapid and economic formation of hermetically sealed joints capable of withstanding working pressures of magnitude such as those often found in the refrigeration process. It is to be understood that the term "malleable tubing", as herein employed, refers to malleable, ductile tubing of a type commonly employed in the refrigeration industry.
Heretofore, numerous attempts have been made to meet existing needs with varying degrees of success. Presently, the applicants are aware of the following U.S. Letters Patents: Nos.
3,124,874 Woolley Mar. 17, 1964 PA1 3,149,860 Hallesy Sept. 22, 1964 PA1 3,149,861 Larsson Sept. 22, 1964 PA1 3,375,026 Szohatzky Mar. 26, 1968 PA1 3,378,282 Demler Apr. 16, 1968 PA1 3,429,587 Kish Feb. 25, 1969 PA1 3,466,066 Dawson Sept. 9, 1969 PA1 3,467,414 Downing Sept. 16, 1969 PA1 3,498,648 Hallesy Mar. 3, 1970 PA1 3,528,689 Roe Sept. 15, 1970 PA1 3,827,727 Moebius Aug. 6, 1974 PA1 3,893,720 Moebius July 8, 1975 PA1 4,026,006 Moebius May 31, 1977 PA1 4,061,367 Moebius Dec. 6, 1977
It is believed that the patents containing the most pertinent teachings are the patents to Moebius, Nos. 3,827,727; 4,026,006; and 4,061,367. While the patentee Moebius apparently has attempted to solve the same, or at least similar problems successfully solved by the applicants, it is noted that the patents do not suggest the structure which embodies the invention hereinafter disclosed and claimed. This distinction is believed to be significant since the patentee necessarily, in each of his patents, will lose the capability of maintaining an hermetic seal in the event a good metal-to-metal contact is not established or is lost for the joint.
It is, therefore, the general purpose of the instant invention to provide an improved union and method of employing the union for forming a fluid-tight joint between lengths of malleable tubing.